a) Field of the Invention
This invention relates to substituted quinolone derivatives or salts thereof excellent in therapeutic effects for peptic ulcer and also to pharmaceuticals containing the same.
b) Description of the Related Art
In today's stressful society, diseases of the digestive system, especially peptic ulcers, have tended to increase and have become a problem. Antiulceratives can be roughly divided into two types, one being the gastric acid secretion inhibition type and the other the defensive factor potentiating type. The former includes H2-blockers led by cimetidine, proton-pump inhibitors represented by omeprazole, and the like, and from the viewpoint of "no acid, no ulcer" (there is no ulcer where no acid exists), features strong inhibition of secretion of gastric acid as the means to cure ulcers. They are sharp-effecting and are used most widely clinically. On the other hand, the latter type make ulceration difficult by enhancing the self-healing ability and resistance of the gastric mucosa, and include gefarnate, teprenone, rebamipide, prostaglandin derivatives, and the like. They feature mild effects and relatively low side effects, and are used for the treatment of gastritis or gastric disorders caused by chemicals or as supplementary medicaments for antiulceratives of the gastric acid secretion inhibition type.
However, the conventional antiulceratives of the gastric acid secretion inhibition type are accompanied by problems such as rebounding of gastric acid secretion by termination of an administration and a recurrence or relapse of an ulcer due to a reduction in Q.O.U.H. (Quality of Ulcer Healing). On the other hand, the antiulceratives of the defensive factor potentiating type, while being of mild activity, are not sharp-effecting. There is accordingly a strong desire for the development of an antiulcerative which has stronger antiulcerative activity yet has low side effects such as rebounding and high safety.